I was wondering if litter sizes are mainly based on the female, or does the male play a part in the size of the litter?

Do you mean the number of puppies born or the actual size of the puppies?

The number of puppies born.

Oh well with cats someone once told me there would be as many in the mothers first litter as there was in her mothers litter. In example:If her mother had 4 including her then she would have four. Although I am not sure on how accurate this info really is...